A desaturation and over-current detection circuit with soft turn-off and under-voltage protection for IGBT was designed in a 0.4 μm standard BCD process. The circuit was designed and built by the Cadence software, and the Hspice software was used to run the simulation and debugging. The results showed that the UVLO output a low level to force the device to be in the off state at the beginning. When the UVLO output a high level, the DESAT was activated and began to detect the collector voltage. Once the collector voltage exceeded the preset threshold voltage of 6.5 V, a soft turn-off action was performed in the device. The soft turn-off duration time was 10 μs. The detection circuit realized the cooperative protection of IGBT by the UVLO and DESAT.